# NCERT Class 9 Maths Chapter 6 Lines and Angles (Latest Edition)

Class 9 Maths NCERT Book Chapter 6 - Lines and Angles is provided here in PDF format. Get the latest edition of the chapter to prepare for your Maths Exam in the 2021-2022 session.

Created On: Jul 16, 2021 19:08 IST
NCERT Class 9 Maths Chapter 6 Lines and Angles

Class 9 Maths Chapter 6 Lines and Angles is available here for download in PDF format. We have provided here the latest edition of the chapter which is published by the NCERT on its official website. We have also provided in this article the link to download the NCERT Solutions for the chapter - Lines and Angles. The chapter and solution PDFs will make a perfect combo for you to prepare for all your school tests and the annual exam 2021-2022.

About Class 9  Maths Chapter 6 Lines and Angles

Class 9 Maths Chapter 6 - Lines and Angles introduces the basic types of angles formed when two lines intersect at various points. It also explains various concepts and types of angles as mentioned below.

Major topics discussed in the chapter are:

→ Basic Terms and Definitions

→ Intersecting Lines and Non-intersecting Lines

→ Pairs of Angles

→ Different Angles formed Transversal of Parallel Lines

→ Lines Parallel to the Same Line

→ Angle Sum Property of a Triangle

A screenshot of the NCERT Class 9 Maths Chapter 6 is given below:

Some important points to revise from the chapter are:

• If a ray stands on a line, then the sum of the two adjacent angles so formed is 180° and vice versa. This property is called as the Linear pair axiom.

• If two lines intersect each other, then the vertically opposite angles are equal.

• If a transversal intersects two parallel lines, then

(i) each pair of corresponding angles is equal,

(ii) each pair of alternate interior angles is equal,

(iii) each pair of interior angles on the same side of the transversal is supplementary.

• If a transversal intersects two lines such that, either

(i) any one pair of corresponding angles is equal, or

(ii) any one pair of alternate interior angles is equal, or

(iii) any one pair of interior angles on the same side of the transversal is supplementary, then the lines are parallel.

• Lines which are parallel to a given line are parallel to each other.

• The sum of the three angles of a triangle is 180°.

• If a side of a triangle is produced, the exterior angle so formed is equal to the sum of the two interior opposite angles.

Try some important questions given below for self-assessment:

1. Two adjacent angles are equal. Is it necessary that each of these angles will be a right angle? Justify your answer.

2. Sum of two angles of a triangle is 90o and their difference is 50o. Find all the angles of the triangle.

3. Prove that vertically opposite are equal.

4. The angles of a triangle are in the ratio 2:3:5. Find the angles of the triangle.

5. Find x, in the given figure:

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